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Horticultural farm cash receipts totaled CAN$8.6 billion in Canada in 2014. Horticultural crops have dominated the Plant Breeders’ Rights Office application submissions. In this paper, we first examine the application pattern of plant breeders’ rights (PBR) for horticultural crops following the enactment of the Canadian Plant Breeders’ Rights Act in 1990. Second, we assess whether stronger intellectual property rights (IPR) are needed to boost plant variety development. Plant breeders’ rights applications and grants data from the Canadian Food Inspection Agency from 1992–2014 are used to examine how PBR applications by public and private institutions have evolved in response to reductions in research and development funding for horticultural crop research by Canadian public institutions and changes to plant variety protection policies. We show that the bulk of PBR applications are for ornamental crops (followed by vegetables and fruits) involving mostly Rosa and Pelargonium and originate from European and U.S. corporations. Agriculture and Agri-Food Canada accounted for 35% and 53% of the total apple and cherry applications, respectively. Since 2005, applications for ornamental varieties have declined, suggesting the perception of a weak intellectual property protection environment. The PBR system allows farm-saved seed or propagating material use, while plant breeders can use germplasm material in new line breeding activities. Stronger IPR and royalty collection systems may promote greater private plant breeding and commercialization of new varieties for the heterogeneous Canadian horticultural crop industry.
White bean is a high-value, important export field crop for farmers in Canada. Effective weed management in white bean is important as this crop is not competitive with weeds. Use of preplant incorporated, preemergence, and postemergence herbicides are effective means for weed control in white bean production in Canada. There are a range of herbicides registered for use on white bean in Canada, but in comparison with other high-acreage field crops such as corn and soybean, the options are relatively limited. This can pose challenges for white bean producers trying to use multiple herbicide modes of action to reduce the evolution of herbicide-resistant weeds and limits management options for troublesome weeds. In particular, management of perennial weeds in white bean with currently registered herbicides is difficult. There is a continued need to evaluate and register additional herbicide options for weed management in white bean in Canada.
In Arabidopsis thaliana (L.) Heynh., the nucleoporin CPR5 negatively regulates the cell cycle regulator CKI. In this short communication, it is shown that a cpr5 mutant is hypersensitive to the plant stress hormones of jasmonic acid, abscisic acid, and ethylene, whereas a cki mutant (sim smr1) is insensitive to these hormones, suggesting that the CPR5–CKI signaling pathway plays a central role in integrating stress responses.
KEYWORDS: Canada fleabane, Glyphosate resistance, preplant herbicides, soybean, vergerette du Canada, résistance au glyphosate, herbicide de présemis, soja
Eight field experiments were conducted during 2013–2015 to determine the dose response of glyphosate-resistant Canada fleabane to preplant metribuzin in a tank mixture with glyphosate in soybean. The predicted metribuzin rates required to achieve 80%, 90%, and 95% visual control of glyphosate-resistant Canada fleabane were 659, 1093, and 1720 g a.i. ha-1 at 4 weeks after application and 783, 1355, and 2237 g a.i. ha-1 at 8 weeks after application, respectively.
KEYWORDS: leaf color variation, pigment, gene expression, Acer palmatum, variation de la couleur des feuilles, pigment, expression des gènes, Acer palmatum
Exterior leaf color is an important trait for ornamental foliage plants but the molecular mechanism underlying the variation in color between yellow- and green-leaf Acer palmatum Thunb. ex Murray is poorly understood. Indeed, chlorophyll (Chl) contents and gene transcriptions were very different between the yellow mutant (YM) and green wild-type (GW) leaves of this species. Here, annual variations of leaf color and pigment contents in two varieties were investigated. Then, transcript levels of six genes involved in Chl metabolism were quantitatively measured using real-time polymerase chain reaction in YM and GW leaves. Compared with GW, the color changes of YM leaves were classified into four typical periods. During the yellow leaf stage, YM showed greatly reduced Chl synthesis and a higher ratio of carotenoid (Car) to Chl than GW. These phenomena may be the main cause of yellow leaves in YM. In addition, expression levels of Chl synthesis genes (ApPORA, ApPORB, ApCAO, and ApCHLG) in YM were very low during this period. Concomitantly, the amount of transcripts of genes for Chl degradation (ApCLH1 and ApCLH2) rose significantly compared with GW. Once YM leaves turned red, the above differences between the two genotypes lessened. Overall, our results indicated that changes in Chl synthesis and degradation may play important roles leading to the yellow leaves of YM A. palmatum.
KEYWORDS: phosphorus uptake efficiency, phosphorus offtake, potato harvest index, phosphorus harvest index, efficacité d’absorption du phosphore, apport de phosphore, indice de récolte de la pomme de terre, indice de récolte du phosphore
This 2-yr (2013 and 2014) study evaluated the variation in tuber yield and selected indices of phosphorus (P) use efficiency of two new potato cultivars [AAC Alta Cloud (AC) and AAC Alta Strong (AS)] versus Russet Burbank (RB), the french fry industry standard. Initial P levels and P saturation index [(P/Al) × 100] ranged from 85 to 89.5 mg P kg-1 and from 4.6% to 5.6%, respectively. A complete randomized block design for each variety was laid out in three adjacent plots with six P fertilization rates. The average tuber yield ranged from 29.06 to 36.81 Mg ha-1 for AC, from 27.56 to 41.50 Mg ha-1 for AS, and from 38.15 to 42.02 Mg ha-1 for RB, with the highest yield observed in 2014. Tuber yield response to P application was described by the quadratic-plus-plateau model for AC and linear-plus-plateau model for AS with a mean critical (above which the yield response to P applications is unlikely) P rate of 40 kg P ha-1. Russet Burbank did not respond to P application. The trends of P uptake efficiency (PUE) for AC and AS mirrored that of tuber yield, while RB had a linear increase in PUE with P rate. The study highlights that current P recommendations for potatoes can be reduced without affecting yield, thus increasing farmers’ economic returns. It also reveals the need to test optimal fertilization levels for new cultivars.
Plant anthocyanin biosynthesis is regulated by a combination of transcription factors. Here, exogenous anthocyanin regulator genes Delila/Rosea1 (Del/Ros1) or Bperu/Colored aleurone1 (B1/C1) were introduced to Lilium ‘Sorbonne’ using an efficient and optimized Agrobacterium tumefaciens (Smith & Towns.) Conn-mediated transformation system. During the B1/C1 transformation, eight types of modified Murashige and Skoog medium for bacterial inoculation and co-cultivation were evaluated. Significant enhancement in putative transformation efficiency was observed upon the removal of KH2PO4, NH4NO3, and KNO3 or with the removal of all the macroelements. Using the optimal medium, 20 s sonication positively affected the transformation while no significant improvement was observed following heat shock treatments. Replacing sucrose in the co-cultivation medium with high concentrations of maltose or glucose also promoted the transformation. Higher transformation efficiencies were observed when using this optimized protocol for the Del/Ros1 transformation. The Del/Ros1 and B1/C1 transformed plantlets appeared light purple during the preliminary regeneration stage, with some deeper purple tissues also observed in Del/Ros1 plantlets. After the transformation was confirmed by polymerase chain reaction and Southern blot, the colour unexpectedly faded to normal green when the transgenic plantlets were rooted, but significant elevations in anthocyanin levels remained in leaves and scales compared with the nontransgenic plantlets. The introduction of these anthocyanin regulator genes may be useful for the modification of Lilium flower colour.
Cold stress is one of the main abiotic stresses faced by winter wheat, which results in significant yield loss, especially in the harsh winter of the Heilongjiang province. Glycine betaine (GB), an important osmolyte in higher plants, helps in the stabilization of the plasma membrane and its protection from cold stress. In the present study, two winter wheat varieties that differ in cold resistance, Dongnongdongmai1 (DM1) and Jimai22 (J22), were planted under natural conditions and used for analyzing relative electrical conductivity, malondialdehyde (MDA) content, betaine aldehyde dehydrogenase (BADH) activity, expression of BADH, and the content of GB. The cold-resistant variety, DM1, showed a greater increase in BADH activity and GB content and decrease in MDA content than J22 under freezing conditions. GB was observed to have an obvious role in inhibiting the MDA content. This was reflected by the expression of BADH and enhanced tolerance to cold stress upon GB accumulation, which helped membrane stabilization. The results of the present study confirmed the role of GB in conferring cold resistance in the DM1 winter cultivar and could benefit other studies aimed at improving the tolerance of other wheat cultivars and other crops.
Superoxide dismutase (SOD) plays an important role in the stress tolerance of higher plants. In the present study, a novel Cu/Zn-SOD gene, SiCSD (accession no. KC912564), was cloned from Saussurea involucrata Kar. & Kir. The deduced amino acid sequence shared 85% identity with Cu/Zn-SOD of Solanum tuberosum L. and Solanum lycopersicum L. Quantitative real-time polymerase chain reaction showed that SiCSD was upregulated by treatments with cold, drought, and oxidative stresses. SiCSD transgenic tobacco plants improved tolerance to drought, freezing, and oxidative stresses and exhibited a higher survival rate, relative water content, photosynthesis efficiency, and higher activities of SODs, catalases, and ascorbate peroxidase, but lower ion leakage and malondialdehyde contents compared with the wild type. These data demonstrate that SiCSD may act as a positive regulator in drought and cold stress by reducing oxidant injury.
The objective of this study was to identify quantitative trait loci (QTL) related to phytophthora root rot (PRR) tolerance and to analyze their genetic effects through two recombinant inbred line populations between tolerance cultivar Hefeng 25 and two susceptible cultivars (Dongnong 93046 for the HD population, including 140 F5:9 lines, and Maple Arrow for the HM population, including 149 F5:10 lines) based on greenhouse evaluation of PRR. A total of five and seven QTL underlying tolerance to PRR were identified in the HD and HM populations, respectively. Phenotypic variation explained by the QTL ranged from 1.27% to 10.41% in the HD population and from 1.68% to 12.65% in the HM population. Of these QTL, three (qHDPRR-4 in the HD population and qHMPRR-1 and qHMPRR-3 in the HM population) were identified in similar genomic regions reported previously. Nine new QTL contributed by Hefeng 25 were found in the present study (four in the HD population and five in the HM population). Three QTL in the HD and five QTL in the HM populations had higher additive effects that were likely to be stable across multiple environments or genetic backgrounds. Moreover, four and five epistatic pairwise QTL were found to underlie tolerance to PRR in the HD and HM populations, respectively.
Challenges in the emasculation of female parent panicles and limited morphological variation among canary seed (Phalaris canariensis L.) genotypes has resulted in a need for molecular markers to assess hybridity and seed purity. Codominant simple sequence repeat (SSR) markers can be used to assess hybridity and purity instead of a grow-out test. A set of 15 SSR markers was used to assess hybridity of 10 F1-derived F2 families developed from a cross between two glabrous lines: a yellow-seeded C05091 (female parent) and a brown-seeded C00038 (male parent). The two most informative SSR markers, CSM8 and CSM39, could confirm that 9 of 10 families were hybrids due to the presence of a marker allele from the male parent. Three SSR markers, CSM58, CSM85, and CSM102, allowed us to assess the genetic identity of four experimental canary seed lines: C08019, C08046, C09052, and C10022. The three markers also identified the physical admixture in 1 of 16 batches of seeds.
Canola (Brassica napus L.) productivity is severely affected by various biotic and abiotic stresses such as insects, pathogens, drought, and cold. Characterization of genes with specific effects on particular stress responses is one of the long-term goals for B. napus genetic improvement. Here we explored the roles of Brassica napus myrosinase-associated protein 1 (BnMyAP1), which was highly represented (expressed) in a B. napus subtractive library developed after leaf damage by the crucifer flea beetle [Phyllotreta cruciferae (Goeze)]. Expression of BnMyAP1 was under different developmental control in B. napus, but it was co-induced in B. napus by flea beetle feeding, Sclerotinia sclerotiorum (Lib.) de Bary infection, drought, and cold. A total of 20 BnMyAPs were represented in different B. napus stress and development expressed sequence tag libraries and indicated larger, more diversified families than were previously known. Overexpression of BnMyAP1 in Arabidopsis thaliana (L.) Heynh. resulted in an increased survival ratio (63%–90%) compared with that of the controls (15%–20%) after S. sclerotiorum infection, which suggests that BnMyAP1 could be used to protect B. napus oilseed and vegetables from the S. sclerotiorum disease.
KEYWORDS: rotational effect, pulses, rhizobacteria, symbiosis, soil water, N mineralization, C to N ratio, effets de l'assolement, légumineuses, rhizobactéries, symbiose, eau du sol, minéralisation du N, ratio C à N
Diverse crop rotations enable the best use of residual soil water and nutrients, thus decreasing necessary production inputs. Here, we determined the effect of cropping sequences on soil residual water and nutrients and the performance of subsequent wheat (Triticum aestivum L.). Nine rotation systems were evaluated at Swift Current, SK, and Brooks, AB, from 2010 to 2014. Pea (P, Pisum sativum L.) and lentil (L, Lens culinaris Medik.) as preceding crops before wheat (W) or the rotation systems with pea (P–P–P–W) or lentil (L–L–L–W) included more than once in the 4-yr rotations had the highest residual soil water and N in the 30–90 cm depth and continuous wheat (W–W–W–W) had the lowest. Preceding pea and lentil increased the grain yield of the subsequent wheat by 26% and 18%, respectively, as compared with continuous wheat. Variance partitioning of redundancy analysis revealed that soil residual water and residual N explained 12.4%–42.7% (average 30%) of the yield variation observed in the subsequent wheat, with the rest of the rotational benefits unexplainable by soil residual water and residual nutrients. Investigation of the factors other than soil water and nutrients that contribute to the succeeding wheat yield may further enhance the rotational effect.
KEYWORDS: additive and nonadditive gene action, additive–dominance model, genetic components of variance, Vr–Wr graph, earliness and yield traits, Triticum aestivum L, action additive et non additive des gènes, modèle des effets additifs et dominants, composantes génétiques de la variance, diagramme Vr–Wr, précocité et caractères liés au rendement, Triticum aestivum L
A half-diallel mating system was used to evaluate six wheat cultivars and their F1 and F2 populations for inheritance of earliness and morphological and yield traits. These genotypes were crossed in a half-diallel fashion during 2010–2011 to get 15 cross combinations. The 6 × 6 wheat F1 and F2 half-diallel populations and their parental cultivars were assessed in a randomized complete block design during 2011–2012 and 2012–2013, respectively. Genotypes revealed significant (P ≤ 0.01) differences for all the traits in both generations. According to scaling tests, an additive–dominance model was partially adequate for all the traits in the F1 and F2 generations. Diallel analysis revealed significant values for additive (D) and dominance (H1 and H2) genetic components of variance for majority traits in both generations, however, the overdominance type of gene action was predominant for inheritance. Additive gene action was observed for days to heading and plant height in the F1 generation and tiller per plant and grain yield per plant in the F2 generation. In the loci (H2 < H1), the majority of the traits showed an unequal proportion of positive and negative genes with asymmetrical distribution among parental genotypes (H2/4H1 < 0.25). Significance of both additive and nonadditive genetic variations suggested integrated breeding strategies with delayed selection for improvement in wheat populations.
We conducted a series of three greenhouse studies to study the allelopathic effects of seven native perennial North American forage species alone and mixed on three problematic weeds including dandelion [Taraxacum officinale (Weber) ex Wigg.], scentless chamomile (Matricaria perforata Mérat), and foxtail barley (Hordeum jubatum L.). Shoot dry weight and root to shoot ratio of weeds were affected by leachate from forage species in all three experiments. In the first experiment, leachate from little blue stem [Schizachyrium scoparium (Michx.) Nash] reduced the shoot dry weight of weeds up to 58%. In the second experiment, leachate of little blue stem, western wheatgrass [Pascopyrum smithii (Rydb.) Löve], and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] reduced shoot dry weight of weeds up to 72% and this number increased up to 90% in the third experiment. In the last experiment, no synergistic effects of mixed leachate from different forage species on shoot dry weight of weeds were observed. In this study, dandelion and foxtail barley allocated less to roots and shoots, respectively. In conclusion, our results showed that root leachate from western wheatgrass, little blue stem, and sideoats grama can reduce the aboveground and belowground growth of weeds. These findings suggest that the use of allelopathic species may provide weed control and management benefits in seeded pastures and native prairie restorations.
Soybean resistant to both glyphosate and dicamba (Roundup Ready 2 Xtend™) has been developed by Monsanto Inc. and was commercially available for the first time in Canada in 2017. Six field trials were conducted over a 2-yr period (2014–2015) at three locations in southwestern Ontario to determine whether there is a benefit of including dicamba in a postemergence application of glyphosate at two application timings for the control of non-glyphosate-resistant weeds in Roundup Ready 2 Xtend™ soybean. Adding dicamba to glyphosate did not increase control of grass weed species. The tank mix of glyphosate and dicamba increased the control of redroot pigweed, common ragweed, common lambsquarters, and lady’s thumb by as much as 14%, 3%, 7%, and 5%, respectively, at 8 weeks after the late-postemergence application. In general, broadleaf weed density and biomass collected 6 weeks after the late-postemergence application was reduced more with dicamba applied alone or together with glyphosate than when glyphosate was applied alone early postemergence. Due to the absence of a grass herbicide, weed interference with dicamba applied alone resulted in a yield loss of 30%–33% while treatments containing glyphosate resulted in a yield loss of only 3%–7%. The tank mix of glyphosate and dicamba improved broadleaf weed control, but it should not be applied alone due to poor control of grass weeds.
An investigation was carried out for two consecutive years to study the suitability of 1-naphthaleneacetic acid (NAA) alone or in combination with calcium chloride (CaCl2) to control preharvest fruit drop and their effect on fruit quality of ‘Red Delicious’ apple (Malus pumila Mill.). The following five treatments combinations were tested: (1) control, the trees sprayed with water only; (2) a single spray with NAA; (3) two sprays with NAA at an interval of 14 d; (4) a single spray with NAA CaCl2; and (5) two sprays with NAA CaCl2 in combination at an interval of 14 d. NAA was sprayed at the rate of 20 mg L-1 and CaCl2 was sprayed at 3 g L-1. NAA applications reduced fruit drop appreciably when sprayed one month before harvest. The spray was effective in retaining the fruit on the tree for ∼14 d and the second spray after the 14 d of the first spray retained the fruit for another ∼14 d; however, the keeping quality of the fruit was reduced. No significant effect of CaCl2 sprays could be observed on maintaining the keeping quality of apple.
Effects of N, P, and K applications alone or in various combinations and ratios were studied on the morphological, physiological, and seed yield attributes and on seed production of calendula. Treatment combinations were control (no N–P–K application), 150 kg ha-1 N, 80 kg ha-1 P, 150 kg ha-1 K, N–P, N–K, P–K, and N–P–K, while in a second experiment, different ratios of N–P–K were compared to determine the best combination and ratio of tested nutrients for optimal growth, quality, yield, and seed production. Plants supplied with N–P–K had vigorous growth, had higher total leaf chlorophyll content, and flowered earlier with greater flower fresh and dry weights, along with improved photosynthetic performance. Plant biomass and seed yield along with leaf N and K were also higher in plants fertilized with N–P–K. In the second experiment, the application of 200–100–100 kg ha-1 N–P–K resulted in maximum growth, flowering, and seed yield, along with higher photosynthetic activity. Increased leaf area and improved leaf nutrient status were observed at 150–150–150 kg ha-1 N–P–K, while 200–200–200 kg ha-1 N–P–K increased stomatal conductance, photosynthetic rate, leaf P, and flower weights. Results demonstrated that a higher level of N along with lower level of P and K are vital for quality calendula flower and seed production.
Xyloglucan-specific endoglucanase inhibitor proteins (XEGIPs) are present in a wide range of dicots, where they are believed to play a role in defense from pathogens. XEGIPs are generally present as two or three copies; however, they are reported to be present as a cluster of 10 copies in potato and tomato on chromosome 1. We have identified a second set of XEGIP-encoding genes, where two inverted copies are present on chromosome 8 of potato (Solanum tuberosum L.). The same set exists in the same order on chromosome 8 of tomato (Solanum pennellii Correll). Transcript expression analysis indicates that XEGIP10 is transcribed only in roots, while XEGIP11 transcripts were not detected under normal growth conditions. Transformed potatoes (‘Bintje’ and ‘Kennebec’) overexpressing these genes did not show any changes in phenology. Foliar screening of transgenic lines for resistance to the late blight pathogen Phytophthora infestans (Mont.) de Bary did not demonstrate a large reduction in disease progression or pathogen sporulation.
AAC Richmond is a white-hulled, spring oat (Avena sativa L.) cultivar developed at the Ottawa Research and Development Centre of Agriculture and Agri-Food Canada in Ottawa, ON. It was supported by the Ontario Cereal Crops Committee in January 2013 for registration and was registered on 20 Feb. 2014 (Canadian Food Inspection Agency no. 7488). AAC Richmond was later maturing and taller and showed higher grain and straw yield than check cultivars in eastern Canada. It was highly resistant to crown rust (Puccinia coronata Corda f. sp. avenae Eriks.).
AAC Noranda is a white-hulled, spring oat (Avena sativa L.) cultivar bred by the Ottawa Research and Development Center of Agriculture and Agri-Food Canada in Ottawa, ON. It was supported for registration by the Ontario Cereal Crops Committee in January 2015 and registered in Canada on 12 Feb. 2016 (Canadian Food Inspection Agency registration no. 7912). AAC Noranda is adapted widely to Canada but more so to Ontario and Zone 1 of Quebec. AAC Noranda has a beta-glucan level around 5.0%, which is distinctly higher than the check cultivars (around 4.3%). It has combined good levels of grain yield, beta-glucan, groat, and oil and is an approved milling oat cultivar by the millers.
AAC Blake is a white-hulled, spring oat (Avena sativa L.) cultivar bred by the Ottawa Research and Development Center of Agriculture and Agri-Food Canada in Ottawa, ON. It was supported for registration by the Ontario Cereal Crops Committee in January 2015 and registered in Canada on 12 Feb. 2016 (Canadian Food Inspection Agency registration no. 7911). AAC Blake yielded significantly higher than control cultivars in both eastern and western Canada. It had significantly better resistance to crown rust (Puccinia coronata Corda f. sp. avenae Eriks.), higher beta-glucan level, but lower groat content than control cultivars.
Roseland is a two-row spring hulless food barley (Hordeum vulgare L. f. sp. nuda) cultivar developed at the Agriculture and Agri-Food Canada Brandon Research and Development Centre in Brandon, MB. It is adapted across all regions of western Canada. Roseland has improved lodging resistance, higher test weight, and better threshability than check cultivar Millhouse and similar flour quality characteristics to Falcon barley. Roseland is resistant to several important barley diseases, including stem rust (Rpg1 gene) and surface-borne smuts.
AAC Almonte is a tan-hulled, covered spring oat (Avena sativa L.) cultivar bred by the Ottawa Research and Development Center of Agriculture and Agri-Food in Ottawa, ON. It was supported for registration by the Ontario Cereal Crops Committee in January 2013 and registered in Canada on 20 Feb. 2014 (registration no. 7487). AAC Almonte is adapted to and has performed well in southern Ontario since its release due in part to its outstanding crown rust (Puccinia coronata Corda f. sp. avenae Eriks.) resistance.
AAC NRG097, a hard red spring wheat (Triticum aestivum L.), was developed at the Swift Current Research and Development Centre of Agriculture and Agri-Food Canada, in Swift Current, SK. AAC NRG097 has grain yield and time to maturity within the range of the checks, a semidwarf stature, and heavier seed mass than the checks. It expressed resistance to prevalent races of both leaf rust and common bunt, while expressing an intermediate level of resistance to Fusarium head blight. It received registration no. 7567 from the Variety Registration Office, Plant Production Division, Canadian Food Inspection Agency (CFIA) on 24 July 2014. AAC NRG097 was granted Plant Breeders’ Rights Certificate no. 5089 by the Plant Breeders’ Rights Office, CFIA on 7 Aug. 2015. It is eligible for grades of Canada Western Special Purpose.
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